<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        li{
            width: 200px;
            height: 50px;
            background-color: blueviolet;
            border: 1px solid #e9d929;
            list-style: none;
            float: left;
        }
    </style>
</head>
<body>
    <ul>
        <li>1</li>
        <li>2</li>
        <li>3</li>
    </ul>
    <script>
        var li = document.querySelector('li')
        console.log(li.offsetLeft);
        console.log(li.offsetRight);
        console.log(li.offsetTop);
    </script>
</body>
</html>